N.C. Gen. Stat. § 115C-550
To assure that all high school graduates possess those minimum skills and that knowledge thought necessary to function in society, each private church school or school of religious charter shall administer at least once in each school year, a nationally standardized test or other nationally standardized equivalent measure selected by the chief administrative officer of such school, to all students enrolled and regularly attending the eleventh grade. The nationally standardized test or other equivalent measurement selected must measure competencies in the verbal and quantitative areas. Each private church school or school of religious charter shall establish a minimum score which must be attained by a student on the selected test in order to be graduated from high school. For one year after the testing, all records shall be made available, subject to G.S. 115C-174.13, at the principal office of such school, at all reasonable times, for annual inspection by a duly authorized representative of the State of North Carolina.
N.C. Gen. Stat. § 115C-550